FunkyMunky

Customer #1 was harrassing me, begging for me phone number, a date etc., and not taking 'no' or 'I'm taken' for an answer. Customer #2 decides to step in (even though I really didn't need it, the gesture seemed honest enough). It worked. Ordinarily I would have thanked my 'rescuer', except for the way he got rid of the pest was thus:"Back off mate, you're hanging onto her like the flies hang around a [racial slur]".

Was I rude?

(ETA: for the record, I'm not a member of the racial group in question, nor are any of my friends, but I still find the slur highly offensive)

I get the impression that the OP is wondering if she should have thanked customer no2. It is a tricky one- because by thanking him she could be seen as implicitly agreeing to the use of the slur. Equally, however rude no2 was in using the slur, he did mean well and was trying to protect her.

I can't honestly say which would be the right thing to do. Thanking someone is not wrong, but then neither is saying nothing because of the use of the slur.

Either response would not be rude in the circumstances, where the OP was placed in a very awkward position.

Since you were at work, I think silence was best. I understand your urge to thank the helper and also to be concerned that by doing so you'd be putting a stamp of approval on the racial slur. But as an employee, you probably don't have the option of 'correcting' a customer's use of a racial slur, either.

As a fellow Aussie, it took me a few perplexed minutes of racking my brain to try and work the slur out and the result has not pleased me . Regardless of what it was, OP it was not you who was rude. I can understand that you seem worried that your stunned silence might be interpreted as complying with or agreeing with the racist statement made, but I think most people would just read it as what it was - stunned silence. I experienced something similar the other day in the supermarket. A fairly young, awkward teenage girl was serving the customer in front of us and discussing how she was allergic to the glue on bandaids (she was itching her arm, which is how the conversation came up). The much-older, slightly creepy guy then leaned in and lecherously said 'You're not allergic to boys though, are you?' and looked to us for smiles at the 'joke'. I was mortified for the girl (who was clearly very uncomfortable with the whole situation) but felt later that my silence might make me in some way complicit in the whole transaction. But it doesn't.

Edited to add: And if you're worried about not 'thanking' the man for his intervention, then I honestly would not give it a second thought. The delivery of said intervention was highly offensive and deserves nothing but silence or censure.